SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23396a0292e65cde25b754f793dca80b981f65f534bf4f7995fb751eb4e27786' 
  AND token = 'mN0cAiDiq5dCc0Ro2IEkfj38kz0ge2pD8q9U/bbFdtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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