SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1903d967e85a327bc501505d3dcaed8c6d455fbe0cbd319428cc99929a6cf2e' 
  AND token = 'd/6km0cvbywO1hpzmz8f5qh7OTDuFi99odoIwjRGmW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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