SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e90fa5d923004e595111b0c31b241ba3caf52b7f4e630820cf990aee2ed98a3' 
  AND token = '4sbvf2qrK5aIbVzdYSn1YpDTbLbRc5/ildgRiWmRvAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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