SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d678c382ca04684adaa537d7d04dc2fcfb6da25c9379ec623e613d85e7acba6' 
  AND token = 'oRysm3n6E6Xzx4XUqJP4sKHjBhBioR2ul08ZFBQoHAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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