SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea2c3ab827cf452b73bba1a2abcb18fab3dd6bba22f662e46f606b35673c4443' 
  AND token = 'SGS3vNOvACaQA4LZ/vGEfmxamvbJawtCWe7PptJaltg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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