SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1faf268258d89ab902e967501f7e269086d874ce55ce947a505b17857282c77f' 
  AND token = 'sLDO2eJ0z14xxS4s8EFiVWjeexvwEsXAgeWP45vf5cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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