SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3bdca1eabf7ed0a7d6888773c29971ef9d9f65f79d9563da38be64f15dace84' 
  AND token = 'FgM0a56bzsXA2XucSDD1kE0z4gMoaqXfmiSOoUL0jFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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