SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c3ece1ff339895278f97481c02291cdbb316fd9ac31daa15d2963606bad34bd' 
  AND token = 'dQIRmycRWSJn/zj2zC3ekrvDHWoHql9ntYDPKRSNzCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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