SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cf72146dd8f53501ad6cf59aeeea7f66edeed4b8df886e71cfe1aebb467b0ae' 
  AND token = 'dsPleXvA2I40sJbgDyEw/PBQ6EoRsfmPNSnlqnN7IwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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