SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5764c6c3fe3785a1a49f2d3155b594e6d8c1c4bfc5461e7137c2ef7c8338b9da' 
  AND token = 'nzmhhDFbpzo44Yv/M9QVMA4YnmzPNY2HTkqFO7/CMvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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