SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43337be0f06478ba3d32df1aa38ae9c7e0eb2e4e2d6800695130947c1fce1c16' 
  AND token = 'Ly8KM56StDbX6etr6NBoxwtBAdEBk1PXFOIlsAfffy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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