SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbe34751b28bc187a73a812a532a07df02b23d85fa629fa1e123d70702d9e488' 
  AND token = 'HtSipwFmuDB3rWl8vxz6XFXBJR7HRYvWNuGh/JJ8hL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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