SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfe5824f1fc30bbcb414a27c4443f02fc135f5cad7d6839f379f0a963130242e' 
  AND token = 'zKBNlncrNRDzz0nHcOzRE+3ejwBMs4GOZTfv1b+FuRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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