SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e80cab05d472039bbc38cf776b87d2bcf835a866bcbc48882789d02bc915533' 
  AND token = 'gyg93gygcf488KxjyCKo3v9H+J8rlfhVaYMTFrBe70g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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