SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b71d42623f8261528033b28b22695c8a5fc761a8f7f0bd7a33b5a5f431531cb1' 
  AND token = 'wVmcLnOF8ANRcRJXHnyeSuPuvTdZjv+kWZDKGkUwjAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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