SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ea6850483b1502c02eab80d904c6d336d2c648a942d3aaab86d1e3350529bb9' 
  AND token = 'm++uaSEpLnEL4cecXGRgnAABUXnebRIidM8xuXAn5qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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