SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de0be05570b8024cfc95d6a034bdc9fc25c34b1f6d28d444e1abb72809ef1832' 
  AND token = 'BCs4GsbcznwhXYjUSQQSHv3Hn/rHgvoEp4+tjHu0nvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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