SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8048309e594bd43d53f3ca85135d881cac28920ecd23b4c9c5243c67c31bd8b6' 
  AND token = 'EmU5QMsX8GhNzUuxMyaBSaI9z2P7snSaIzgn1U7ngL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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