SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e373d06673f66668466c2b1137d0f1a224a91e9ddaf7e04f3dc028beea075ca' 
  AND token = 'dXTfqO924LQgCH/lnYO9/CvL8Qz/vghwDB/agvxYvbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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