SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7112c48c9e361612fc100434f7839517c7cd8d1393ab1bac38bbb99f4524798' 
  AND token = 'OmkfCnLUlQZgk6YbFBtRB1dB1u8/5vVFtyzmqxisppw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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