SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '657564112d147e90c9c1ce7d1568758ac7169dc6b3ac3af78c6a7f98514291bc' 
  AND token = 'RqGGYtTdtjqIllA9Zd4FZSEni5aFEaUeWByonMiQuTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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