SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd49e232869686bc558d3627b46b6b794c0bf815628136dc16898af6e3a361357' 
  AND token = 'Ax7Z0i6/ZR5r/hj7yjoAyW3t1tkilGYCBTwrOyt/Wwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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