SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05bdfb5f4dcce2e6872183b93dc03d253b644c50c4a742729a67691a12969f9e' 
  AND token = '+/2J36GUPitwqb9zie3ZCjbqGwmKUgb5F0Fg5Bsy5bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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