SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09dbf3cccb8545b9f9eaadc42c4e6f2be30c6c8183c0591cf2bd8c4cf6b39f37' 
  AND token = 'mfBakry2QiNto3L9qC0yAVtk8ORMBg9SD3rb/izo3x4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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