SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd0d3cb29391d0d1e8b4b4875042deedb0b308f190535197cd12a79e341612cc' 
  AND token = 'ym63mvRW9Aw/CYegcANfmYVPI2XSh8EmM9Li8zclRdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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