SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab97ccd8b95299c5f7aebd28815608124bce462dba5e102b817e015b41342ee5' 
  AND token = '7YYbaLyFXQXDDG8NrIMXcfJ3LUfxuLeSySin+hfWi24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}