SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66a2e6a131d21acd9a09aaab9ead028d863d1a721b94b95726f25fd369e6644c' 
  AND token = 'tTqiU92qp0a1D9H0Qd6uP4qjCaXMG6yTOvdFxgQ/pQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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