SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '651484dd7b24af3c703b3c8a56ec37d046fae425598fe2e28e26bb5cde0235c6' 
  AND token = 'krAiQFUY+ElD9T1Qwx+h4FvIaoLKNZyh7Br7EimYWkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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