SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b26371c7851645ec31c965ad12fc45472b4ad88823f3c7f339e867008c6572b7' 
  AND token = 'qknbVgGox44Cgwo184VBQc2zl3pKqghJjmE9FgzFLe8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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