SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5284f85193b602f9ced89ee3bb9587e5965788e777fb9cca2e571a99b208fb48' 
  AND token = 'Ak76noQ8KbIws95LCYibCtw6cnpgv0ZnQ9evbvp5kY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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