SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a9cc228f222bac1622a82d62cb092f92aa6da4b068a6aaf35d26bed68d5d5ba' 
  AND token = 'kWVv6i2E0s3M9hpi9vkWD2EEirUqe0o9GruMw50JKLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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