SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '03a3698ac937f8e736ae8f3159d85fa4b078267e7f9728ce66f31438bea9cc99' 
  AND token = 'QTPV+3oqTIww6WxaoD6GO1bdKEENv7fzebQIVhMEW2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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