SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '862635d62cdaba582fe4f1d5b913ff57ae74657d200f197f4ced5342692beb1c' 
  AND token = 'i+IK24dqDYj/upF4u4x78k6C/XHmPJZXY7EmcHQp4J0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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