SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '214c65cddf7e100c3153fba4def9151a00e0eb35d306ef09c5a87f60d042c074' 
  AND token = 'iJCGb8q67dYyiVOiHLTV4bvOJc1zVVmI8P/p2cLUprI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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