SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e0918569de3316e53588a776a1c2b2b5877d92d191addb0d2df8c6d8855a51f' 
  AND token = 'Wojq3EvCPyUBSsaN3pEDQRl509GziU+sWrpEYPFPeWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}