SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7833181508b091d8c197723384afaff91041370e2f0f47810eafac675de770e7' 
  AND token = 'Z03P65oDIwpvh46Gq15HjQLvCLVNBeNWzkXiJIF2594=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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