SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5817e05861690bda720634fd90c95e5f7c33c9d6ac9a86470231e40792f7385' 
  AND token = 'p/Ib8134eDeOVOV32kgiFkgXe65+L9MeyXCul4GTXks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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