SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0821b9445f463ad911554c4901bf5373bfcb35ab382b0886f56574bc9ef56d14' 
  AND token = 'CxSaurNOtCCEiJJDwPGbMC5RfSj+hKAdEHhyM9eZ0VU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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