SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f628935461ea6bf93017c0aa9c4e1ebdebde82ca89cd4e92f78bd82695b6aa9a' 
  AND token = 'Td9MDS1bwI7CTxfHFfff2bSMvu5KjfR8z9OCnXDL5QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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