SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7521fa84525903bd3885d950d0ae4d8c33901eec8d628e65879e95a424b649fe' 
  AND token = 'NaV22z7qD9m8KYB4wXs3vqZD4vTu8uCgRrZCif+M0Rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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