SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d687cb4676f7822e830f365add354a7c89c703cfb39ecb8728069a3bb2dfdff' 
  AND token = 'U97gczCHpd/oIhJY0kizVuVf2z4ngYOkyFAmJgaOZ7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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