SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4364705b274b6c9ba1454b4fec7765f36d51e52e778313f6bfc60ef7ca09a613' 
  AND token = 'foFlBZdZziEb9ti/2a/qScw+vVGWZNGrvx15ouMXgQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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