SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5a9568cf4dfc65522687d22cb0c9dd6274d3ad06785e4bcf343156813b1d140' 
  AND token = 'uXtZxtLCSVjjTGrjO3dVuuv865Paf2ASZeRsxKWqDG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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