SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9563f4225840bc277157841b6b99dfbf0b84427f704a9b37401d38e710521c1' 
  AND token = 'Z2U5obig4KibSbFUJc/NqiXiPyyE1lkmYtPQAxFHhtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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