SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43dc6abb46ff622ba7238665114e38d12164075cffbcfc0f6fb94a5cfa7c289e' 
  AND token = 'WbsLOcCDJtkBEL+vsG3VMHCZhKo/p6y9Bf12ZPJg0Bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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