SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a2c9236d30df0303e7118abedd7df33c90d2ea48bb86855e676d39ed5d63ea4' 
  AND token = 'thTwUJoebpQgV9F2vkfwEEXFAwEtyDSIfIvYl8pd9n0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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