SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1a0c2e0a71187390f2ebaa7e13a43616e68bd907e1a47567a4b41fbd2bf5e77' 
  AND token = 'KgmxQ6HE/cE2HDymTD15zb/odWXKl1VQ4/JtNFGX+ww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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