SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1827345b502d6528949d8ccdfb379bc0631c7cf053dd92220e9de31ea3ac80c9' 
  AND token = 'WotavZmuIRjxf25W1+FtMgvLmIW3XyftC7TyowmR11E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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