SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd257d77ec073a273daabf2984d3b85cc6e80348fe3dfe55fa5c4a12d67ef3768' 
  AND token = 'Q2Hf2kKkZS55XNLpyb95lIbfQ5aSxXqz1ndtd6A10fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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