SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd2a7a10d87198cc5be721604dd3aa6d0f7e5d225bdb3ee6af84110ab9b6c842' 
  AND token = 'M935KhY9ZVTqd4ddDa48md+e9Xlo9ESSulMWJ7iJrb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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