SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4555c871cc4551209fdf8d695106a05d0d945bc4e034e9ee2cf7fbb3e6762c2' 
  AND token = 'TqRdQgdM6Jctzkgy04cYU0iWJP9ZhXf3batlgwYUIqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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