SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2939734e69dfc7909890762836c6c33691b1792def01c0d75028f84b15f44723' 
  AND token = 'm4r6vY/GI4j1zHVVJbRujSapQFxidqhZUCpb5ZZPwhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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