SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27510ef43dcffef86cd304ee9531ed57bb0d832030c2d91fc3e0b4cb8ca3c4f8' 
  AND token = 'fSq5glDZ4qYijtNxkgCqtJByOd922zM91F7vh6WIIps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}