SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c2b22bfe39052d1b4046ad15fc6f09f5793e03b4326795eb9f179c806d87b99' 
  AND token = 'JyFUCbJaHmK9F2F1AaYw1zD8ZQOSawaWnevg1jLGYFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}