SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52c3c094cd4c1e60e159f622618aa785bec6b4647b780e86b59ca5175450fa4c' 
  AND token = 'Kdmx50BGwR39HvRoXB7zvyB5JRVG0SCRNmBqGL2mycg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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