SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6f8f4b7c7aa76a56c4ad1c41e6d985d0281c9203d812dfd6bac992c4186f52' 
  AND token = 'JngM9HjxDaqFUuYtNx574rqTrN0Jw8k6FHO11lycKpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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