SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '139015a6527741ead82fa67ac23297ca6403951afdf58319b4310ed7e8031563' 
  AND token = 'hAa/E9UYkkwJLCAemrYzmY72+gXeEZWwacL3V1i5jVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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