SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffd47295c5716edfa2bc1404058ff5fa33dcaad35a65b2ecba5ff096856f851f' 
  AND token = 'fAz/HTYoCJHPTJFQKwieCZOkH9CFnfjpuFRit6V1nb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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