SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9863c4c0f2e12ea43fe4ede7a0a225f70cc8b6395abe9ee9380f7f8126c9d315' 
  AND token = '/QSTlF6G1+ZdDU2u5kZCoJwjbZWn+PJUWaXatmR3WtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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