SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ed45c952a6e13e2fee316216608cd70ffc4babca61ff5b91f628a7e3e39d7aa' 
  AND token = 'OAqJb7DV72pDokbfub0J3yxHHEhZ4YrU5PKrsBWZpZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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