SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c49c35fad614fac382b09bb787d5cb7d668efef6672e9e68991e452692c5959' 
  AND token = 'FlSHHjP5T4d9SRlJsPh2O7+fCmtf6z5VGoMO2XwkJhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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