SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2307958958037f8061492021ec3ef79d618bd7d606fdc2221100f3991378623' 
  AND token = 'tYaxjV2KKeIpi4colx6CljO92aFd3GPPZiSH6xN6f+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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