SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fefac513cd8b2a3e74ada64207172fa73ac9e7e3b3bb3bf1444b982bdf58bbf4' 
  AND token = 'ZSqQCJn+85BNfZiJOo91TGcBOK2pgjwUsPggfgUO+Ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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