SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12333e9d6c5576163deede80977faf4bea1835a19c72d3f66d119ddcf1f25b0f' 
  AND token = '7j43J5CgLc+ZasCWmZTR13NfKw+H5gZnS/GaAllGY+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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