SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aa477c40fff8d1979be3677f0bc5e326889fa8f6b4f0fecb382cfd9d94e73cf' 
  AND token = 'DmfDt3gmV4vM2CDfgqG5inLrKtQfPwamXcSGQFezSEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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