SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30750fc428c0071d3a9e632131689db5eb441016445190a24e4b915af632c94d' 
  AND token = 'qHKFZZf0xLd64xFZWSoNgG/Rr7XrHIpM6MkEbgyi5/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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