SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1465857942fe61aef21177a7b3c57a51cd0abc8d251938b55458eb08c071ca9' 
  AND token = 'j7MOr3rBeAFPseXmF8Ff6sLEG8By8NVtn6rHp0UbuYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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